Aortic onchocercosis and elaeophorosis in traditional TSZ-cattle in Tabora (Tanzania): prevalence and pathology.

Onchocerca armillata was found in 3838 (95.4%) and Elaeophora poeli in 70 (1.7%) out of 4025 samples of aortas collected from cattle slaughtered at Tabora in Tanzania during the calendar year 1988. Gross lesions of the affected aortas varied from mild to severe, characterised by parasitic tunnels, nodules and corrugated calcified ridges on the aortic wall. Histological sections revealed changes as a result of tissue reaction against the parasites which were embedded into the intima of affected aortas. Calcification and hyaline degeneration were common features. The high prevalence of O. armillata and the extensive pathological lesions observed would seem to warrant assessment of the importance of onchocercosis in animal production in the tropics. Meanwhile, further studies are required to elucidate the epizootiology of aortic onchocercosis and elaeophorosis in order to devise practicable diagnosis, treatment and control methods.